In the environment of telecommunications systems there has been a steady trend toward automating what was originally operator assistance traffic. Much current activity is directed to responding to directory assistance calls by processing voice frequency instructions from the caller without operator intervention. The instructions are used by an automatic speech recognition unit to generate data signals corresponding to recognized voice frequency signals. The data signals are then used to search a database for a directory listing to derive the desired directory number. A system of this type is described in U.S. Pat. No. 4,979,206 issued Dec. 18, 1990. Further examples of use of voice recognition in automation of telephone operator assistance calls is found in U.S. Pat. No. 5,163,083, issued Nov. 10, 1992; U.S. Pat. No. 5,185,781, issued Feb. 9, 1993; and U.S. Pat. No. 5,181,237, issued Jan. 19, 1993, to Dowden et al.
Another proposed use for speech recognition in a telecommunications network is identity verification by voice verification. This is the process of verifying the person's claimed identity by analyzing a sample of that person's voice. This form of security is based on the premise that each person can be uniquely identified by his or her voice. The degree of security afforded by a verification technique depends on how well the verification algorithm discriminates the voice of an authorized user from all unauthorized users. While it would be desirable to use voice verification to verify the identity of a telephone caller, such schemes to date have not been implemented in a fully satisfactory manner. Illustrative proposals for implementing voice verification are described in U.S. Pat. No. 5,297,194, issued Mar. 22, 1994, to Hunt et al.; U.S. Pat. No. 4,718,096, issued Jan. 5, 1988, to William S. Meisel; U.S. Pat. No. 4,999,613, issued Mar. 12, 1991, to Williamson et al. for a Remote Confinement System; and U.S. Pat. No. 5,023,901, issued Jun. 11, 1991, to Sloan et al., for a Surveillance System.
In the surveillance or home incarceration art, it has also been proposed to use various optical surveillance devices such as cameras. U.S. Pat. No. 4,511,886, issued Apr. 16, 1985, to Michael J. Rodgriguez describes an electronic security and surveillance system. In that system a central monitoring station is connected to a plurality of remote installations or subscribers by a transmission medium having a finite bandwidth. Each remote installation includes a plurality of surveillance equipment, including video, audio, and alarm signals, associated with a plurality of monitored locations. The security information collected by the surveillance equipment is serially sampled by a switcher which provides that information to an interface unit transmitter. The interface unit transmitter compresses the video information and decodes the alarm information and processes the resulting signal for transmission. The information received at the central station is demodulated and the alarm information monitored by means of a command computer.
U.S. Pat. No. 4,458,266, issued Jul. 3, 1984, to Trevor W. Mahoney, describes another surveillance system. The arrangement detects motion by means of a video detector comprising at least one TV camera directed at the surveillance area. The image from the camera is displayed on a TV screen, divided into a matrix of detection zones which are thereafter processed in sequential manner, and the results of the sequential processing compared to earlier scans to detect motion.
U.S. Pat. No. 3,885,090, issued May 20, 1975, to Richard W. Rosenbaum, describes a continuous automatic surveillance system. This system utilizes a video tape recorder to continuously record video images of an area under surveillance on an endless tape loop. When a sensor detects a disturbance the sensor starts an interval timer which stops the video recorder after a predetermined period of time following the disturbance. A plurality of read heads are positioned around the endless tape loop to selectively monitor one of a plurality of past times. By superimposing a grid pattern on the video image and providing predetermined space markings on the floor or wall under surveillance, the movements of a subject may be measured and tabulated to form a motion print characteristic of the subject for later identification.